Methods and arrangements for handling unreliable scheduling grants in a telecommunication network

ABSTRACT

The present invention relates to methods and arrangements for handling unreliable scheduling grants in a WCDMA-communication system. A user equipment detects that a received scheduling grant is unreliable and adjust its serving grant based on that information. The user equipment is also able to report continuously received unreliable grants as an event to the network, allowing the network to adapt its operation to reduce the unreliable grants.

CLAIM OF PRIORITY

This application is a continuation of U.S. patent application Ser. No.11/815,733, filed Aug. 7, 2007, now U.S. Pat. No. 8,526,357 B2, which isa 371 of PCT/EP05/52275, filed May 18, 2005, which claims the benefit ofSwedish Patent Application No. 0500311.6, filed Feb. 7, 2005. Thecontents of these documents are hereby incorporated by reference herein.

TECHNICAL FIELD

The present invention relates to communication systems in general,specifically to methods and arrangements for handling unreliablescheduling grants in a WCDMA-communication system.

BACKGROUND

In WCDMA enhanced uplink the Node B sends scheduling commands to theuser equipments (UE) at every Transmission Time Interval (TTI), which atpresent can be either 2 ms or 10 ms. Each user equipment maintains aserving grant (SG) by increasing or decreasing its transmitted bit rateas dictated by the scheduling grants received from the network. Thischange in the transmitted bit rate is in turn achieved by applying theselection of the Transport Format Combination (TFC) in the userequipment.

A scheduling grant or scheduling grant message provides an indicationfrom e.g. the Node B of both serving and non-serving radio link sets tothe user equipment about the maximum amount of uplink resources it mayuse. The scheduling grants are sent once per Transmission Time Intervalor even less frequently. The serving grant (SG) represents the uplinkresources that the user equipment is presently utilizing on the servingradio link set i.e. bit rate.

The following two types of grant channels have been specified [1] [2] inthe standard according to prior art: Enhanced Relative Grant Channel(E-RGCH) and Enhanced Absolute Grant Channel (E-AGCH). The E-RGCHchannel is transmitted by a serving radio link set (RLS) as well as byone or several non-serving RLS:s. This is shown in FIG. 1. The servingRLS transmits the commands “DOWN”, “UP”, and “HOLD”, which maycorrespond, e.g., to −1, +1, and 0 respectively. On the other hand,non-serving RLS:s transmits either “DOWN” or “HOLD”, which maycorrespond to +1 or 0 respectively. Only the serving RLS uses the E-AGCHchannel to send the absolute grant, which corresponds to the maximumallowed bit rate for the user equipment.

In soft handover (SHO) the user equipment receives absolute and/orrelative grants from the serving RLS, whereas the non-serving RLS sendsonly the relative grant. If any of the relative grants is “DOWN”, theuser equipment estimates its New SG as follows according to prior art:New SG=last bit rate used−δ

The δ in the above equation may correspond to the user equipmenttransmit power or bit rate. If none of the relative grants is “DOWN”then the New SG will be according to the absolute/relative grantsreceived from the serving RLS.

The existing solutions according to prior art imply at least twoproblems:

Firstly, not all scheduling grants are reliable. There is always a riskthat the power of the grant is such that, e.g., a “DOWN” grant can beerroneously treated as a “HOLD” grant, which in turn results in too muchinterference in the system.

Secondly, the network is not aware whether the scheduling grants that itis transmitting are reliable or not.

Therefore, there is a need for solutions providing handling ofunreliable scheduling grants at the user equipment and for reducing theoccurrence of unreliable grants in the network.

SUMMARY

It is an object of the present invention to provide methods andarrangements for handling unreliable scheduling grants in acommunication system, more specifically it is an object of the presentinvention to enable a user equipment to estimate new serving grantsbased on reliable and unreliable scheduling grants and to enable acommunication network to handle unreliable scheduling grants.

It is a further object of the present invention to enable acommunication network to improve the reliability of the schedulinggrants.

Briefly, according to the invention a user equipment detects that areceived scheduling grant is unreliable and adjust its serving grantbased on that information. According to a specific embodiment, the userequipment is also able to report continuously received unreliable grantsas an event to the network, allowing the network to adapt its operationto reduce the unreliable grants. The term continuously is used in thesense that a plurality of consecutive received scheduling grants areunreliable.

The invention proposes a new method in a user equipment in response toreceiving unreliable scheduling grants. The method generally includes:the user equipment detects unreliable received relative schedulinggrants; the user equipment takes appropriate action, i.e. adjust itsserving grant to prevent interference.

Optionally the user equipment reports an event to the network if grantsare continuously received unreliably. Subsequently, and optionally, thenetwork adjusts the power offset of the grant channel and/or thedownlink load of the corresponding cell.

Advantages of the present invention include:

-   -   The unreliable scheduling grants will be detected by the user        equipment and such grants shall not be taken into account during        soft handover combining process.    -   The user equipment does not transmit at a rate higher than the        network can tolerate, preventing bad uplink reception quality.    -   The user equipment transmits at a rate, which in some scenario        can allow the base station to detect that it is transmitting an        unreliable grant.    -   The network is able to know if the scheduling grants are        received reliably or not.    -   The network will be able to take some radio resource management        (RRM) actions, which will eventually alleviate the problem of        transmitting unreliable grants.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention, together with further objects and advantages thereof, maybest be understood by making reference to the following descriptiontaken together with the accompanying drawings, in which:

FIG. 1 illustrates the transmission of scheduling grants in E-DCH;

FIG. 2 illustrates unreliabile power regions for relative schedulinggrants;

FIG. 3 is a schematic flow diagram of an embodiment of a methodaccording to the invention;

FIG. 4 is a schematic flow diagram of another embodiment of a methodaccording to the invention;

FIG. 5 is a schematic flow diagram of a further embodiment of a methodaccording to the invention;

FIG. 6 is an embodiment of arrangements according to the invention.

ABBREVIATIONS

UE User Equipment

UL TPC Uplink Transmit Power Control

E-RGCH Enhanced Relative Grant Channel

E-AGCH Enhanced Absolute Grant Channel

TTI Transmission Time Interval

SG Serving Grant

TFC Transport Format Combination

RLS Radio Link Set

E-DCH Enhanced Dedicated Channel

WCDMA Wideband Code Division Multiple Access

RRM Radio Resource Management

3GPP 3^(rd) Generation Partnership Project

RNC Radio Network Controller

SHO Soft Handover

DETAILED DESCRIPTION

A first problem with prior art is that the user equipment (UE) does notcarry out any reliability check of the received scheduling grants, whichmight cause the UE to misinterpret the grants especially for softhandover. In other words, some grant messages received by the UE can beunreliable. This could happen due to number of reasons: noisy link,lower transmit power on the grant channel due to inappropriate powersetting on the grant channels, bad UE receiver performance, etc.

For instance, in case a “DOWN” grant is interpreted as “HOLD”, the userequipment will follow the scheduling grant from the serving RLS, whichmay lead to excessive interference at the non-serving or neighboringcells. On the other hand, detection of “HOLD” as “DOWN” will lead tothroughput loss. It is important to note that the base station does nothave any information about the load situation in the neighboring cellsimplying that all the base stations send their respective schedulinggrants independently.

The false detection of “DOWN” as “HOLD” is a more extreme situationsince there will be an impact on the uplink interference. However, thereis also throughput loss if “UP” (from the serving RLS) is interpreted as“HOLD” or “HOLD” (from neighboring cell) is interpreted as “DOWN”.Similarly, the network or base stations will experience moreinterference if the UE treats “HOLD” (from the serving RLS) as “UP”.

Another problem with the current solution is that the communicationnetwork is not aware whether the transmitted grants are reliable or not,i.e. there is no mechanism by which the network can be informed that thereceived grants are unreliable. This means that a plurality ofunreliable grants could be continuously transmitted without anycorrective action by the network, resulting in excessive interference inthe neighboring cells.

Basically, the present invention addresses the handling of unreliablescheduling grants in a user equipment and a network. The user equipmentidentifies such unreliable grants and treat them according to one of thepossible embodiments stated below in the detailed description while thenetwork then assures reliability by help of one of the embodiments asstated below in the detailed description. The solution according to thepresent invention is applicable but not limited for single link andparticularly advantageous in soft handover scenarios.

The invention will be described in the context of a user equipment UEcommunicating with a serving radio link set RLS and receiving schedulinggrants from both the serving RLS and at least one non-serving RLS, as isillustrated in FIG. 1.

With reference to FIG. 1 a basic situation in which the presentinvention can be applicable is that a user equipment (UE) receives aplurality of relative scheduling grants from the serving RLS and atleast one non-serving RLS. The UE needs to detect if any of the relativegrants from the non-serving RLS is reliable or not. One indication of anunreliable scheduling grant is that the received power from the grantschannel lies in one of the unreliable power regions or intervals δ₁,δ₂indicated in to FIG. 2.

Upon detection of at least one unreliable scheduling grant the UE needsto take appropriate action to dynamically adapt its serving grant (SG)such that the neighboring cells do not receive excessive interference.In the following a number of embodiments for this adjustment will bedescribed.

Basically, the UE needs to detect if any of the relative grants receivedfrom the non-serving RLS is reliable or not. Unreliability can bedetected, e.g., if the received power from the grant channel lies in anunreliable region or power interval δ₁,δ₂, as illustrated in FIG. 2. Theregion is unreliable in the sense that for a grant with a received powerwithin that interval it is difficult to distinguish a “DOWN” grant froma “HOLD” grant, and to distinguish a “HOLD” grant from an “UP” grant. Ifany of the relative grants is unreliable the UE adapts the serving grant(SG) such that the neighboring cells don't receive excessiveinterference. In other words, the UE dynamically adapts its SG.

With reference to FIG. 3, according to a basic embodiment of a method, auser equipment detects S1 that at least one received scheduling grant isunreliable, subsequently the UE evaluates or interprets S2 theunreliable grant(s) and estimates S3 a new serving grant based at leaston the interpretation.

According to a specific embodiment, if the user equipment receives aplurality of consecutive unreliable scheduling grants it reports S4 anevent to the network, i.e. the radio network controller.

According to the preferred embodiment, the user equipment interprets orevaluates S2 the detected unreliable scheduling grants, and estimates S3the new serving grant based on that interpretation.

According to an alternative embodiment, a scheduling grant is detectedS1 as unreliable if the received power is within a predetermined powerinterval or region. There is a first such unreliable region δ₁ betweenthe “DOWN” command and the “HOLD” command, and second region δ₁ betweenthe “HOLD” command and the “UP” command.

In the following, a number of specific embodiments concerning theevaluation or interpretation S2 of the unreliable scheduling grants andthe estimation S3 of new serving grants will be described.

Generally, the user equipment interprets the unreliable scheduling grantbased on some criteria, and estimates the new serving grant based onthat interpretation. Also, the interpreting step can comprise ignoringan unreliable grant, thus not using the unreliable grant in theestimation of the new serving grant. Further, the interpretation can beaided by some additional measurements. However, the collective idea ofthe embodiments is that the UE detects that a scheduling grant isunreliable, and takes this into consideration when estimating the newserving grant.

According to a preferred embodiment of the present invention, the UEevaluates or interprets S2 received unreliable relative schedulinggrants as “HOLD” when estimating S3 the new serving grant. This meansthat the UE shall follow other reliable grant(s). In case all therelative grants are unreliable the UE shall treat all the grants are“HOLD”, this means the serving relative grant will not change. Possiblecombinations of relative grants are listed below:

-   -   “UP” and “Unreliable”→“UP”    -   “DOWN” and “Unreliable”→“DOWN”    -   “HOLD” and “Unreliable”→“HOLD”    -   “Unreliable” and “Unreliable”→“HOLD”

According to another specific embodiment of the present invention, theUE disregards the relative scheduling grant from non-serving RLS when atleast one relative grant is unreliable. The evaluating step S2 in thiscase means that the unreliable relative scheduling grant is determinednever to have been received. This means that the UE maintains the lastserving grant for which the corresponding relative grants all werereliable. Hence, the UE estimates S3 its serving grant (SG) as follows:SG(k)=SG(m)where k denotes the current TTI, and m is the last TTI, when the UE hasreceived reliable relative grants from all the RLS. Possiblecombinations of grants comprise:

-   -   “UP” and “Unreliable”→“HOLD”    -   “DOWN” and “Unreliable”→“HOLD”    -   “HOLD” and “Unreliable”→“HOLD”    -   “Unreliable” and “Unreliable”→“HOLD”

However, the embodiment described above does not provide precautions forthe case that the UE still transmits at a too high data rate if one ofthe RLS wants to decrease the transmitted bit rate. Hence, a furtherspecific embodiment is a further elaboration of this embodiment, that incase of one or more unreliable grants, the UE only follows the “DOWN”grant or a new serving grant if that grant is lower than the previousgrant:SG(k)=min{SG(m),G _(serv) _(—) _(cell)(k)}where G_(serv) _(—) _(cell) denotes the scheduling grant (relative orabsolute) received from the serving cell in the current TTI. Possiblecombinations of grants comprise:

-   -   “UP” and “Unreliable”→“HOLD”    -   “DOWN” and “Unreliable”→“DOWN”    -   “HOLD” and “Unreliable”→“HOLD”    -   “Unreliable” and “Unreliable”→“HOLD”

It is still another specific embodiment that the network sends uplinkinterference thresholds, i.e. the user equipment UE receives suchthresholds, common for all cells or different for different cells, forthe neighboring cells in the neighboring cell lists. When unreliablescheduling grant(s) is/are detected S1, the UE then measures the pathloss to the neighboring cell and estimate the UL interference. The UEthen adjusts its transmit power using the TFC selection in order to keepthe UL interference below the threshold set by the network. In this way,the interference on the neighboring cells can be avoided. This methodhas the advantage that there is a maximum interference limit that the UEcan cause to any neighboring cell even if the grant signaling is totallyunreliable. Even if the downlink is totally gone for a while, the UEwill be able to limit the interference caused. A cell that is not in theactive set is protected just before it is about to be added to theactive set and becomes a non-serving or serving cell. Further, the UEmay also be able to transmit at higher rate, unlike the previousembodiments, if the estimated interference is low. The idea of settinguplink interference thresholds to avoid interference can also be appliedto other types of uplink channels, e.g. simple DCH.

This embodiment can be used in combination with all the previousembodiments of the invention.

According to yet another specific embodiment of a method according tothe invention, it is possible for the UE to utilize other informationfor evaluating or interpreting an unreliable relative scheduling grantfrom the network.

In E-DCH transmission fast power control is used. If radio links areunreliable, the UE may, according to a specific embodiment, also utilizethe UL TPC commands, which are sent on the downlink, i.e. from the nodeB to the UE, to assist the interpreting of relative grants from thenon-serving RLS, i.e. the UL TPC commands can indicate the quality ofthe uplink. An UL TPC command “DOWN” implies that the uplink of thecorresponding radio link is good and vice versa. If UL TPC command is“DOWN” (i.e. good uplink) and the scheduling grant is unreliable, thenthe UE can interpret the scheduling grant as “HOLD”. Hence, the UE canthen simply follow the grant from the serving cell. Similarly, if TPCcommand is “UP” (i.e. bad uplink) and the scheduling grant is“unreliable”, then the UE can consider the scheduling grant as “DOWN”.

When assuming ‘1’ as logical value for the “DOWN” UL TPC command and ‘0’as the logical value for the “UP” UL TPC command and when denoting

${TPC}_{UL\_ TTI} = \left\{ {\begin{matrix}{1;} & {{UP}\mspace{14mu}{Command}} \\{0;} & {{{DOWN}\mspace{14mu}{Command}}\;}\end{matrix},} \right.$the algorithm can be summarized as follows:

If the received ‘Relative Grant’ R_(g) is unreliable thenR _(g)=(−1)·TPC_(UL) _(—) _(TTI) R _(g)=1×TPC_(UL) _(—) _(TTI).

Note that R_(g)=(−1) means “DOWN” and R_(g)=0 means “HOLD”.

TPC_(UL) _(—) _(TTI) is based on the combined decisions of all theTPC_(UL) commands received during one TTI (2 ms or 10 ms), e.g. if themajority of TPC_(UL) are UP, then TPC_(UL) _(—) _(TTI) is UP and viceversa.

This solution is feasible in case the TPC commands are also detectedreliably. According to the document 3GPP TS25.101 “UE radio transmissionand reception (FDD)” [6] issued by the 3^(rd) Generation PartnershipProject the UE is required to detect if the received TPC commands arereliable or not. However, there is no indication to the network if theTPC commands are received reliably or not. Therefore, it must also beproposed that the UE does an event reporting in case a number M of TPCcommands are unreliable during a certain time (the same principle as forunreliable grants described above). Consequently, the network canincrease the power offsets on the DL DPCCH or reduce the downlink loadto ensure that the subsequent UL TPC commands are also receivedreliably. Currently the UE reports an out-of-sync, which is an extremesituation where the link is about to be disconnected.

The above-described examples comprise the case for two receivedscheduling grants. However, the same principle applies to cases withmore than two scheduling grants.

The above-described embodiments act so as to enable the user equipmentto properly evaluate unreliable scheduling grants, but do not give anyindication on how to reduce the occurrence of unreliable grants.Consequently, network measures are necessary in case of unreliablegrants. This is necessary in order to reduce the number of unreliabletransmitted scheduling grants and consequently reducing the unnecessaryinterference in the system.

With reference to FIG. 4, according to a basic embodiment of a method ofthe invention, the network receives S10 a report in the event ofcontinuously received unreliable scheduling grants from a userequipment, and initiates S11 an adjustment of power offsets for thescheduling grant channels in the system.

If received scheduling grants in a soft handover scenario areunreliable, the UE can use the possible solutions as explained above forthe user equipment to ensure that the neighboring cells are notinterfered. However, it is also important that the network is informedif the scheduling grants are continuously transmitted unreliably. Thiswill allow the network to take some radio resource management (RRM)related actions.

One proposed embodiment of this solution is that if N scheduling grantsare received unreliably over a measurement period of T₁ ms, then thisevent (U_(g)) is reported S4 to and received at S10 a serving networkunit e.g. the radio network controller (RNC) using RRC signaling. Thenetwork configures the values of the parameters (N and T₁) using RRCsignaling. If the network receives S10 the event (U_(g)) from the UE, ittakes some radio resource management measures S11 to ensure that the UEreceives the subsequent scheduling grants reliably. For example, thenetwork can, according to a specific embodiment, increase the poweroffsets on the grant channel or it can, according to another embodiment,reduce the downlink load so that downlink interference is decreased andeventually the grant commands become less noisy.

According to prior art a node, e.g. Node B, can be unaware that thescheduling grants it is transmitting are unreliably received. It wouldtherefore be beneficial to prevent the actual transmission of unreliablegrants, or detect them before they even arrive at the user equipment.

Therefore, according to a basic embodiment of a method, with referenceto FIG. 5, comprises the Node B detecting S20 unreliably transmittedscheduling grants and subsequently requesting S21 the serving unit e.g.radio network controller RNC to review the power offset for the grantchannels.

More specifically, one or more unreliable scheduling grants may in somecases result in UE transmitting either at lower or higher data ratesthan expected by the radio base station. For example, the combination ofreliable “UP” and unreliable “DOWN” would lead to data rate that ishigher than expected at the base station that transmits unreliable“DOWN”-command. This unexpected data rate can be detected S20 at thebase station or Node B, which in turn can request S21 the RNC to reviewthe power offsets of the scheduling grant channels. The RNC in turn canincrease the power offset or take any appropriate action, e.g. reducedownlink load.

The impact of unreliable grants is more critical in soft handoversituations as this causes the interference at the neighboring basestations. But it is also important for the UE to check the reliabilityof the command in single link scenarios. In the single link case thereis a risk that, on the one hand, the serving cells may receive too muchinterference and, on the other hand, the resources may beunder-utilized. In case of single link the UE simply treats anunreliable scheduling grant as “HOLD”. This means the UE transmitsaccording to the last reliable grant using the same principle asdescribed above for the user equipment. In single link case this means:

-   -   “Unreliable=HOLD”

The UE may also utilize the UL TPC commands, as described previously, toassist the reliable detection of at least the relative scheduling grantfrom the serving RLS.

In case N scheduling commands are detected unreliably during a timeperiod of T₁ ms, the UE can also report this event to the network, whichin turn can take some RRM actions as stated in the paragraph above onreporting of unreliable grants and RRM-actions. It is also possible touse the base station power adjustments as described above.

Arrangements adapted for implementing the above-described methods willbe described with reference to FIG. 6.

An embodiment of an arrangement in a user equipment according to theinvention comprises a detection unit 11 for detecting unreliablereceived scheduling grants, an optional interpretation or evaluationunit 12 for evaluating or interpreting the unreliable received grants,and an estimation unit 13 for estimating or calculating a new servinggrant for the user equipment UE based on the evaluation of theunreliable grants and possibly some other information as well.Optionally, the arrangement comprises a report unit 14 which is adaptedto report an event to a serving unit of the network, e.g. radio networkcontroller, if unreliable grants are received continuously at the userequipment UE.

According to a further embodiment, the arrangement comprises a unit forreceiving uplink interference thresholds for neighboring cells in aneighboring cell list. The receiving unit is adapted to, in response todetection of unreliable grants, measure the path loss of the neighboringcell and adjust its transmit power.

Another specific embodiment comprises a unit for receiving UL TPCcommands from a serving unit in the network e.g. base station, and theinterpretation unit 21 is adapted to interpret the detected unreliablegrants based on the UL TPC commands.

For all the above-described embodiment of the arrangement in the userequipment, the detecting unit 11 can detect single received unreliablegrants and/or multiple unreliable grants.

Also with reference to FIG. 6, an embodiment of a node, e.g. Node B, ina telecommunication system comprises a detection unit 50 for detectingtransmitted unreliable scheduling grants, and a request unit 51 forrequesting a serving unit, e.g. radio network controller, to review andpossibly adjust the power offsets for the scheduling grants channelsbased on the detected unreliable transmitted scheduling grants.

Also with reference to FIG. 6, an embodiment of a serving unit, e.g.radio network controller, according to the invention comprises areceiving unit 40 for receiving event reports from user equipment and aninitiating unit 41 for initiating radio resource managing (RRM)procedures in response to the received event report. Such RRM actionscan include increasing power offsets on the grants channel, reducingdownlink load, and/or removing the unreliable radio link or replacing itwith a reliable radio link.

In summary, the user equipment UE needs to detect if any of the receivedscheduling grants RLS are unreliable. It is thus necessary to definedifferent ways by which the user equipment could set its new servinggrant (SG) in case one or more scheduling grants are unreliable. Theuser equipment reports for instance an event U_(g) to the network, e.g.the RNC, on the radio RRC signaling if N scheduling grants areunreliably received over a certain period of time. In case the networkreceives said U_(g) event, the network takes an appropriate measure, forexample to increase the power offset of the corresponding grant channel.Another possibility is to reduce the downlink load in correspondingcell(s), thereby decreasing interference and improving detection of thescheduling grants by the UE. In certain scenarios, the node B can detectif it is transmitting unreliable grants or not. This detection could bebased on the difference between the expected bit rate and the actuallytransmitted bit rate of the UE. The node B can then request the RNC toadjust power offsets of the grant channels.

The present invention thus describes new methods and arrangements foruser equipment and network units in case the user equipment receivesunreliable scheduling grants. The user equipment detects unreliablegrants, takes appropriate actions and reports an event to the network,e.g. if grants are continuously received unreliably. The network adjuststhe power offset of the grant channel and/or the downlink load of thecorresponding cell. The embodiments described above are merely given asexamples, and it should be understood that the present invention is notlimited thereto. Further modifications, changes, and improvementsretaining the basic underlying principles disclosed and claimed hereinare within the scope of the invention. It is also implied that thevarious methods and arrangements according to the invention can becombined with each other and other functionalities, without departingfrom the main inventive concept.

REFERENCES

-   [1]. 3GPP TS 25.211“Physical channels and mapping of transport    channels onto physical channels (FDD)”-   [2]. 3GPP TS 25.214 “Physical layer procedures (FDD)”.-   [3]. 3GPP TS 25.302 “Services provided by the physical layer”.-   [4]. 3GPP TS 25.321 “MAC specifications”.-   [5]. 3GPP TS 25.331, “RRC protocol specifications”.-   [6]. 3GPP TS 25.101, “UE radio transmission and reception (FDD)”.

The invention claimed is:
 1. A method in a user equipment (UE) in atelecommunication network for handling unreliable relative schedulinggrants of relative scheduling grants comprising one of a HOLD command,an UP command and a DOWN command applicable in one of a single link anda soft handover scenario, the method comprising the steps of: detecting,by the UE, at least one unreliable received relative scheduling grant;interpreting, by the UE, any detected unreliable relative schedulinggrant as HOLD; and estimating, by the UE, a new serving grant based atleast on the detection and the interpretation, the estimating comprisingadapting the serving grant by following reliable relative schedulinggrants and by treating unreliable relative scheduling grants as HOLD. 2.The method according to claim 1, wherein the adapting the serving grantwhen estimating the new serving grant comprises maintaining the servinggrant when receiving at least one reliable relative scheduling grantwith a HOLD command and when all relative scheduling grants areunreliable, and otherwise the adapting the serving grant compriseschanging the serving grant.
 3. The method according to claim 1, furthercomprising a step of reporting, by the UE, an event to saidtelecommunication network on continuously received unreliable schedulinggrants during a given period of time.
 4. The method according to claim3, wherein the UE reports the event if a predetermined number ofunreliable scheduling grants have been received during the given periodof time.
 5. The method according to claim 1, further comprisingfollowing steps: receiving, by the UE, uplink interference thresholdsfor neighboring cells in a neighboring cells list; and in response to atleast one detected unreliable received scheduling grant: measuring, bythe UE, the path loss to the neighboring cell and estimating ULinterference, and adjusting, by the UE, transmit power using the TFCselection to keep the interference below the uplink interferencethreshold.
 6. The method according to any of claim 1, further comprisingsteps of: receiving, by the UE, UL TPC commands from a base station; andinterpreting, by the UE, the at least one unreliable received schedulinggrant based on the received UL TPC commands.
 7. The method according toclaim 6, wherein the UE interprets an unreliable received schedulinggrant as HOLD if the UL TPC command is DOWN.
 8. The method according toclaim 6, wherein the UE interprets an unreliable received schedulinggrant as DOWN if the UL TPC command is UP.
 9. The method according toclaim 6, wherein the UE interprets said at least one unreliable receivedscheduling grant according to:R _(g)=−1×TPC_(UL) _(—) _(TTI) where R_(g)=interpreted unreliable grant,and TPCUL=1 for UP command and TPCUL=0 for DOWN command, TPC_(UL) _(—)_(TTI) is based on the combined decisions of all the TPC_(UL) commandsreceived during one TTI if majority TPC_(UL) are UP, then TPC_(UL) _(—)_(TTI) is UP and vice versa.
 10. The method according to any of claim 1,wherein said detecting step further comprises determining if thereceived power is within a predetermined interval.
 11. The methodaccording to claim 10, wherein said predetermined interval is anunreliable power region.
 12. The method according to claim 11, whereinsaid unreliable region is defined by a first and a second thresholdvalue.
 13. The method according to claim 1, wherein the detecting stepfurther comprising detecting a plurality of unreliable receivedscheduling grants.
 14. The method according to claim 1, wherein thedetecting step further comprises detecting only one unreliable receivedscheduling grant.
 15. An arrangement in a user equipment in atelecommunication network, the arrangement comprising: means fordetecting at least one unreliable received scheduling grant; means forinterpreting any detected unreliable relative scheduling grant as HOLD;and means for estimating a new serving grant based at least on thedetection and the interpretation, said means for estimating adapted tofollow reliable relative scheduling grants and to treat unreliablerelative scheduling grants as HOLD.
 16. The arrangement according toclaim 15, further comprising means for reporting an event to a servingunit in said telecommunication network on continuously receivedunreliable scheduling grants during a given period of time.
 17. Thearrangement according to claim 15, further comprising means forreceiving uplink interference thresholds for neighboring cells in aneighboring cells list; and said receiving means adapted in response toat least one detected unreliable received scheduling grant to: measuringthe path loss to the neighboring cell and estimating UL interference,and adjusting transmit power using the TFC selection to keep theinterference below the uplink interference threshold.
 18. Thearrangement according to claim 17, further comprising means forreceiving UL TPC commands from a base station; and said interpretingmeans adapted to interpret the at least one unreliable received grantbased on the received UL TPC commands.
 19. A user equipment in atelecommunication network, the user equipment comprising: a processor;and a memory that stores processor-executable instructions where theprocessor interfaces with the memory and executes theprocessor-executable instructions to effectuate performance of followingacts: detecting at least one unreliable received scheduling grant;interpreting any detected unreliable relative scheduling grant as HOLD;and estimating a new serving grant based at least on the detection andthe interpretation, said estimating adapted to follow reliable relativescheduling grants and to treat unreliable relative scheduling grants asHOLD.
 20. The user equipment according to claim 19, wherein theprocessor interfaces with the memory and executes theprocessor-executable instructions to effectuate performance of followingact: reporting an event to a serving unit in said telecommunicationnetwork on continuously received unreliable scheduling grants during agiven period of time.
 21. The user equipment according to claim 19,wherein the processor interfaces with the memory and executes theprocessor-executable instructions to effectuate performance of followingacts: receiving uplink interference thresholds for neighboring cells ina neighboring cells list, and in response to at least one detectedunreliable received scheduling grant: measuring the path loss to theneighboring cell and estimating UL interference, and adjusting transmitpower using the TFC selection to keep the interference below the uplinkinterference threshold.
 22. The user equipment according to claim 19,wherein the processor interfaces with the memory and executes theprocessor-executable instructions to effectuate performance of followingacts: receiving UL TPC commands from a base station; and interpretingthe at least one unreliable received grant based on the received UL TPCcommands.
 23. A method in a user equipment (UE) in a telecommunicationnetwork for handling unreliable relative scheduling grants, the methodcomprising: receiving, by the UE, a relative scheduling grant, whereinthe received relative scheduling grant is one of at least a HOLD commandand a DOWN command; detecting, by the UE, if the received relativescheduling grant is a reliable relative scheduling grant or anunreliable relative scheduling grant; interpreting, by the UE, anydetected unreliable relative scheduling grant as a HOLD command; andestimating, by the UE, a serving grant based at least on the detectionand the interpretation, the estimating comprising adapting the servinggrant by following the reliable relative scheduling grant and bytreating the unreliable relative scheduling grant as a HOLD command,wherein the serving grant dictates a transmitted bit rate.
 24. A userequipment (UE) in a telecommunication network for handling unreliablerelative scheduling grants, the UE comprising: at least one processor;and, at least one memory that stores processor-executable instructions,wherein the at least one processor interfaces with the at least onememory to execute the processor-executable instructions, whereby said UEis operable to: receive a relative scheduling grant, wherein thereceived relative scheduling grant is one of at least a HOLD command anda DOWN command; detect if the received relative scheduling grant is areliable relative scheduling grant or an unreliable relative schedulinggrant; interpret any detected unreliable relative scheduling grant as aHOLD command; and estimate a serving grant based at least on thedetection and the interpretation, the estimate comprising adapting theserving grant by following the reliable relative scheduling grant and bytreating the unreliable relative scheduling grant as a HOLD command,wherein the serving grant dictates a transmitted bit rate.